A film capacitor is a device that has a structure in which dielectric films and metal layers are disposed alternately, and can store an electric charge.
In recent years, a film capacitor has been increasingly reduced in size and increased in capacity, and has become easily generate heat when driven. Therefore, a resin film that is used as the dielectric film of a film capacitor has been required to exhibit better heat resistance.
A reduction in thickness has been desired for the dielectric film in order to reduce the size of a film capacitor. However, when the thickness of the dielectric film is reduced, the dielectric film tends to exhibit inferior withstand voltage properties and inferior workability. Note that the term “withstand voltage properties” used herein in connection with the dielectric film means that the dielectric film maintains an insulating state even at a high voltage, and the term “workability” used herein in connection with the dielectric film means that the dielectric film ensures that the film capacitor can be produced in a stable manner on an industrial scale.
Patent Literature 1 discloses a film capacitor that uses a film obtained by forming a hydrogenated norbornene-based ring-opening polymer or the like.